睾丸间质细胞内体的细胞化学研究  

Cytochemical Study of Endosomes in Leydig Cells

作　　者：汤雪明[1] 张蕙心[1] 陈晓群[1] 

机构地区：[1]上海第二医科大学生物物理教研室

出　　处：《电子显微学报》1997年第3期339-346,共8页Journal of Chinese Electron Microscopy Society

摘　　要：电镜细胞化学实验结果表明，在睾丸间质细胞中早期内体在形态上表现为一种形状不规则的低密度多泡体，其管状突起可能含有回收到细胞表面的受体。晚期内体在形态上表现为高密度多泡体，接受来自高尔基体的含有溶酶体的运输小泡，呈不同程度的ＣＭＰ酶阳性反应。Endocytic tracers and marker enzyme of lysosomal elements were used to analyze the early and late endosomes in Leydig cells.Tracer experiment showed that hCG gold,ConA gold,WGA gold and CF took the same lysosomal pathway of endocytosis.They binded to their binding sites or receptors at the cell surface and rapidly internalized into endocytic vesicles at 5 minutes after injection.The tracers were next found in small pale multivesiculars (MVBs) at 15 minutes and in large pale MVBs at 30 minutes after injection.The small pale MVBs had a irregular shape with attached tubular membranous extensions,whereas the large pale MVBs usually had a spherical shape.At 1 hour,dense MVBs contained tracers,but most of the lysosomes were unlabeled.The lysosomes became labeled at the 2 hour and late time intervals.The dense MVBs and lysosomes often showed a very close association with autophagosomes,which also became labeled with tracers at late time intervals. Cytochemical experiment showed that,in contract to lysosomes which were CMPase positive,the small and large pale MVBs were CMPase negative.The dense MVBs showed CMPase reactivity in different degree.Some dense MVBs were slightly reactive,and others were strongly reactive.The late autophagosomes together with the dense MVBs and lysosomes showed strong CMPase reactivity. These results indicated that,in Leydig cells four ligands all take the lysosomal pathway of endocytosis.In this pathway,the pale MVBs function as early or sorting endosomes in which recycling receptors are sorted from lysosomal targeted ligands and the tubular regions are proposed to contain receptors destined to be recycled.The dense MVBs function as late endosomes which appear incapable of fusing with newly formed endocytic vesicles,but accept transport vesicles with lysosomal enzymes from the Golgi apparatus and ultimately mature into lysosomes.

关 键 词：内体 多泡体 溶酶体 细胞化学 睾丸 间质细胞 

分 类 号：R329.464[医药卫生—人体解剖和组织胚胎学] Q954.592[医药卫生—基础医学]